Long term longitudinal studies are uniquely valuable for the investigation of mental health and mental disorders. However, due to the difficulties encountered in conducting such studies, only a relatively few are carried out. Because this kind of research requires such a great investment of time and money, it is imperative that the best of these studies be thoroughly mined. This can be facilitated by making the data accessible, at the appropriate time, to investigators from outside the original research team. NIMH has established as a priority the promotion of longitudinal mental health research and has identified the development of national data archives as one of the primary aims within the general objective of promoting longitudinal mental health research. In response to the NIMH initiative, this proposal requests funds to develop a program for acquiring longitudinal mental health data by the Henry A. Murray Research Center of Radcliffe College. The project proposed is a two year feasibility study, including planning and pilot stages of a longer range data acquisition program. The project would establish an Advisory Committee of authorities in various mental health fields. The Committee, along with project staff, would identify and evaluate studies to be considered for archiving, develop a plan for data acquisition and processing, investigate alternative modes of data storage, and prepare reports on relevant ethical and technical issues. During the second year, several studies would be fully acquired. The project also includes the development of a comprehensive computerized index of longitudinal mental health studies available from other data archives and from individual investigators. This index would allow researchers seeking data sets appropriate to their particular research needs to survey a wide range of studies in order to choose those with the desired sample, instrumentation and design. The Murray Research Center, which is a social and behavioral sciences data archive with a special focus on longitudinal research, is a very appropriate site for developing these resources.